Method of separating and purifying spent solvent generated in nuclear
fuel cycle
    1.
    发明授权
    Method of separating and purifying spent solvent generated in nuclear fuel cycle 失效
    在核燃料循环中分离和净化产生溶剂的方法

    公开(公告)号:US5110507A

    公开(公告)日:1992-05-05

    申请号:US673064

    申请日:1991-03-22

    IPC分类号: G21C19/46 G21F9/08

    CPC分类号: G21F9/08

    摘要: A method of separating and purifying a spent solvent generated in a nuclear fuel cycle and containing a phosphate and a higher hydrocarbon. This method comprises treating the spent solvent at a temperature not greater than the freezing point of the higher hydrocarbon but not less than the freezing point of the phosphate to selectively freeze the higher hydrocarbon, and separating a resulting frozen solid mainly composed of the higher hydrocarbon from a remaining solution containing the phosphate in a higher concentration. The remaining solution may further be subjected to low-temperature vacuum distillation to separate the solution into the phosphate and a deterioration product thereof.

    Method of treating high-level radioactive waste liquid
    6.
    发明授权
    Method of treating high-level radioactive waste liquid 失效
    高放射性废液处理方法

    公开(公告)号:US4980093A

    公开(公告)日:1990-12-25

    申请号:US362913

    申请日:1989-06-08

    IPC分类号: G21F9/06 G21F9/00 G21F9/08

    CPC分类号: G21F9/08

    摘要: A high-level radioactive waste liquid, produced in a reprocessing plant, is treated by a freeze-drying step. A low-level radioactive waste liquid containing water, nitric acid and nuclides is obtained from the sublimate of the freeze-drying step. Fission products, actinides, corrosion products (iron, chromium, nickel, etc.), sodium nitrate and sodium hydroxide, not sublimated, are separated as a residue. An alkaline solution such as sodium hydroxide solution is added to the residue to dissolve sodium nitrate and sodium hydroxide. The dissolved nitrate and hydroxide are then separated from the residue containing fission products and the corrosion products.

    Method for thermal decomposition treatment of radioactive waste
    7.
    发明授权
    Method for thermal decomposition treatment of radioactive waste 失效
    放射性废物热分解处理方法

    公开(公告)号:US4895678A

    公开(公告)日:1990-01-23

    申请号:US363305

    申请日:1989-06-08

    IPC分类号: G21F9/06 G21F9/14 G21F9/30

    摘要: A method for thermal decomposition treatment of a radioactive waste uses an apparatus comprising a container for holding molten matter of a radioactive waste containing a sodium compound, a pair of electrodes contacting the molten matter, and a power source for applying voltage between the electrodes while changing the polarity thereof every several tens of seconds. In this apparatus, the molten matter can be heated in the container by Joule heat, which is evolved by electric current directly flowed through the molten matter, so that the sodium compound contained in the radioactive waste can be decomposed, vaporized and removed to recover a stabilized radioactive solid as a residue in the container.

    摘要翻译: 放射性废物的热分解处理方法使用的装置包括容纳含有钠化合物的放射性废物的熔融物质的容器,与熔融物接触的一对电极以及在电极之间施加电压的电源,同时改变 其极性每隔几十秒。 在该装置中,可以通过焦耳热在容器中加热熔融物质,焦耳热通过直接流过熔融物质的电流放出,使得放射性废物中所含的钠化合物能够分解,蒸发并除去 稳定的放射性固体作为容器中的残留物。

    Method of recovering and storing radioactive iodine by freeze vacuum
drying process
    9.
    发明授权
    Method of recovering and storing radioactive iodine by freeze vacuum drying process 失效
    通过冷冻真空干燥过程回收和储存放射性碘的方法

    公开(公告)号:US5252258A

    公开(公告)日:1993-10-12

    申请号:US746818

    申请日:1991-08-15

    摘要: The invention provides a method of recovering and storing radioactive iodine by a freeze vacuum drying process, in which off-gas generated when spent fuel is subjected to shearing and dissolving treatments is scrubbed and, when necessary, is subjected to a precipitation treatment by addition of additives, after which waste liquid containing radioactive iodine is freeze-dried by a freeze vacuum drying process to recover radioactive iodine as iodine compounds. As a result, since the radioactive iodine does not vaporize, release of the radioactive iodine into the environment can be eliminated. In addition, consumption of a collecting agent such as silver zeolite for collecting vaporized radioactive iodine can be reduced. The iodine compounds containing the recovered radioactive iodine is given the same composition as a stable, naturally occurring mineral and is solidified and mineralized as by a high-pressure press. This makes it possible to store long half-life .sup.129 I radioactive iodine safely for an extended period by sealing recovered radioactive iodine in stable minerals for a long period of time.

    摘要翻译: 本发明提供一种通过冷冻真空干燥方法回收和储存放射性碘的方法,其中废燃料经受剪切和溶解处理时产生的废气被擦洗,并且在必要时通过加入沉淀处理进行沉淀处理 添加剂,然后通过冷冻真空干燥法将含有放射性碘的废液冷冻干燥,以回收作为碘化合物的放射性碘。 结果,由于放射性碘不蒸发,因此可以消除放射性碘向环境的释放。 此外,可以减少用于收集蒸发的放射性碘的收集剂如银沸石的消耗。 含有回收的放射性碘的碘化合物具有与稳定的天然存在的矿物相同的组成,并通过高压压机固化和矿化。 这可以通过长时间密封稳定矿物中的回收放射性碘,长时间保存长半衰期的129I放射性碘。

    Method of treatment of radioactive liquid waste
    10.
    发明授权
    Method of treatment of radioactive liquid waste 失效
    放射性废物处理方法

    公开(公告)号:US4844838A

    公开(公告)日:1989-07-04

    申请号:US154213

    申请日:1988-02-10

    IPC分类号: G21F9/06

    CPC分类号: G21F9/06

    摘要: A method of treatment of a radioactive liquid waste containing fission products and a thermally decomposable sodium compound which comprises heating the liquid waste to convert the sodium compound into oxides of sodium, converting the oxides into sodium, hydroxide, reacting the sodium hydroxide with an alcohol to form a sodium alcoholate, separating the sodium alcoholate from an impurity residue essentially comprising fission products, decomposing the separated sodium alcoholate to form sodium hydroxide and recovering the sodium hydroxide.

    摘要翻译: 一种处理包含裂变产物和可热分解钠化合物的放射性废液的方法,包括加热液体废物以将钠化合物转化成钠的氧化物,将氧化物转化为钠,氢氧化物,使氢氧化钠与醇反应 形成醇钠,将醇钠与基本上包含裂变产物的杂质残留物分离,将分离的醇钠分解形成氢氧化钠并回收氢氧化钠。